Optical protective screen with improved visibility

ABSTRACT

An optical protective screen for improved visibility is provided including an electric motor for moving a transparent sheet or film in a transport direction, which sheet or film is disposed in a field of vision of an optical apparatus or human observer. A cleaning mechanism formed from brushes or squeegees or the like, which are oriented generally transversely to the transport direction of the sheet or film are, disposed on at least one side of the field of vision and are applied against said sheet or film to clean it.

BACKGROUND OF THE INVENTION

The invention relates to an optical protective screen for improvedvisibility intended to be disposed in the field of view of an opticalapparatus or a human observer.

Fine particles in motion, e.g. streams of dust or dirt, can deposit on aprotective mask, window, lens, or the like, leading to reducedvisibility which is a safety hazard e.g. for a motorcyclist.

A known protective device comprises a plurality of superposed thintransparent films, disposed on, e.g., the visor or mask of a motorcyclehelmet. As each successive film becomes soiled, the motorcyclist removesit, exposing the next film. The overall thickness of the initialaggregate is limited, so as to avoid distortion of the field of view.Consequently, the useful life of one aggregate is limited, because thenumber of films which can be used in one aggregate is limited. Moreover,the motorcyclist must divert his attention while manipulating the deviceto remove a soiled film; this itself risks accidents.

Another known device which is applied to the visor or mask of amotorcycle helmet comprises a reel or the like, of transparent film,which is unrolled in front of the visor. Once the film is entirely used,it is replaced by reloading the device in a manner similar to reloadingfilm in a photographic camera. The manipulations needed to replace thefilm in this device are somewhat complex. Also, the user is obliged tocarry a spare reel of film, which is inconvenient.

SUMMARY OF THE INVENTION

The object of the present invention is to devise an optical protectivescreen which enables one to improve the visibility of a particular fieldof view, and which avoids the complex manipulations involved in filmreplacement, in that the inventive screen utilizes a cleaning system forthe film.

The inventive screen which achieves this object is an optical protectivescreen for improved visibility, comprised of drive means to transport,move or displace, a transparent sheet or film in a transport direction,which sheet or film is disposed in a field of vision of an opticalapparatus or a human observer; characterized in that cleaning meanscomprising brushes (or squeegees or the like hereinafter, "brushes"),oriented generally transversely to the transport direction of the sheetor film, are disposed on at least one side of the field of vision andare applied against said sheet or film.

As the film is being transported, the brushes rub against the film toremove soils and leave the film clean and clear. In this way, bycleaning and reusing the film, one avoids continual replacement of usedfilm. Thereby one greatly increases the service life of the film. Theinventive device is particularly well suited for providing improvedvisibility under difficult ambient conditions.

According to a particular embodiment, the screen is comprised of a frame(or housing) having a window opening, which frame has two enclosuresdisposed near the lateral sides of the window, wherewith the sheet orfilm comprises a film which is transported in the window between the twoenclosures, the transporting being alternately in one direction and thenthe other, with the aid of drive means suitable for moving the film, andwherewith the brushes are disposed at or near the respective sides ofthe window.

With this embodiment, the cleaning is accomplished by contact of thebrushes with the film, as the back-and-forth displacement of the film iscarried out. The cleaning is improved by employing a plurality ofbrushes disposed against both faces of the film.

According to a first variant embodiment, the screen is comprised of tworespective hollow reels disposed in the enclosures, wherewith the filmis wound up onto and unwound from said reels.

The use of hollow reels provides spaces to accommodate the drive means,thereby reducing the overall dimensions and weight of the device, andreducing the number of parts needed for the drive means.

According to a second variant embodiment, the frame is comprised ofstorage components disposed at the aforesaid enclosures.

With this variant embodiment, part of the storage space is used toaccommodate the film. As the film is transported, it is movedtranslationally in the interior of said space, instead of being wound uponto a reel. As an example, the storage components may comprise armswhereby the screen is mounted on a motorcycle helmet.

According to a preferred embodiment, the drive means comprise anelectric motor disposed coaxially in one of said reels, designated thefirst reel, which first reel is connected via the film to a second reelhaving a (re)winding spring which spring is disposed on a support whichis disposed coaxially on (or in) said second reel.

The use of electric motor drive means for transporting the film allowsone to avoid manual manipulation. Manual manipulation is undesirablebecause it inevitably distracts the user's attention. The electric motorserves to drive the first reel, with one end of the film being woundonto said reel; at the same time, the other end of the film is unwoundfrom the second reel. A spring, preferably a torsion spring, is disposedcoaxially with and interiorly of the second reel, wherewith said springis tensioned as the film is unwound from said reel.

Subsequently, the film is unwound from the first reel by reversing therotational direction of the motor. During this process, the springtension is utilized to automatically wind the film onto the second reel.As seen, the described drive system is a convenient means of generatingalternate back-and-forth movement of the film. The spring also serves tomaintain a slight tension in the film as film transport is carried out.

According to a fourth embodiment, the enclosures contain a cleaningliquid and are provided with sealing means to prevent leakage of saidliquid, said sealing means comprising the brushes (or squeegees or thelike) which are disposed at the respective sides of the film.

The combined use of a cleaning liquid and brushes results in a higherdegree of cleaning and clarity of the film. The cleaning liquid maycomprise a liquid which facilitates dissolution of the soils depositedon the film. Once the liquid has achieved its effect, the brushes thenwipe away excess liquid present on the film. Leakage of the cleaningliquid from the enclosures is avoided by the sealing effect of thebrushes.

According to a particular embodiment, the brushes are inclined withrespect to the transport direction of the film.

With this embodiment, the inclination of the brushes tends to impel thesoils to be removed in a preferred direction. As the film is displaced,the soils present on the film tend to force ahead the soils alreadyaccumulated on the brushes. Thus the inclined brushes more efficientlyremove accumulated soils.

According to a preferred embodiment, the brushes are retracted out ofcontact with the film when the film is displaced in one direction, andare returned to their contacting status when the film is displaced inthe other direction, so as to wipe away excess cleaning liquid; further,the screen has sealing means comprised of wiping-nubs (squeegees or thelike), disposed transversely to the transport direction of the film,which nubs or the like serve to lightly pinch said film.

This embodiment serves to avoid a situation wherein, during thetransporting of the film, soils present on the film accumulate in thevicinity of the brushes on the sides of the window, which accumulationcan occur if the brushes are permanently held in contact with the film.As film transport proceeds, there is a risk that some of suchaccumulated soil material will be released by the brushes and picked upby the film, forming tracks or the like which are detrimental to goodvisibility. With the described embodiment, the brushes disposed on thelateral side where the film is being wound up onto a reel are retracted,such that when the film is being wound up the brushes do not wipe awaysoils, but subsquently when the film is being unwound from the reel thebrushes are brought back into contact with the film, whereby soils areretained on the side of the brushes facing said reel, and excesscleaning liquid is removed. With this arrangement, the chance that soilswill be returned to the field of vision is reduced. Moreover, soils haveless tendency to accumulate (by agglomeration or the like) at thebrushes, because the liquid promotes cleaning of the film (e.g.washing-away of soils from the film) before the brushes exert theirwiping action.

Other advantages and features of the invention will be apparent from thefollowing description of an inventive protective screen for improvedvisibility, with reference to the accompanying drawings. The describedscreen is particularly intended to be disposed on the visor or mask of amotorcycle helmet.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is an overall perspective view of a protective screen disposed ona motorcycle helmet;

FIG. 2 is an exploded front view of the screen, showing in particularthe driving means for the film, and the means of storing the film inreels;

FIG. 3 is an overhead (plan) view of the screen with a cover thereofhaving been removed, showing in particular the mounting of the brusheswhich clean the film.

FIG. 4 is a perspective view showing a variant embodiment of the meansof storage of the film;

FIG. 5 is a view of the transport mechanism of the film corresponding toFIG. 2, in a variant wherein two electric motors are employed to drivethe film;

FIG. 6 is a schematic perspective view illustrating a variant in whichthe brushes are inclined so as to improve soils-removal;

FIG. 7 is a partial cross sectional view through the line VII-VII ofFIG. 2, showing a preferred variant embodiment employing retractablymounted brushes;

FIG. 8 is a schematic perspective view showing a variant employingchannels for removal of soils and cleaning liquid; and

FIG. 9 is a schematic front view of an embodiment having a protectivescreen in the form of a pair of protective eyeglasses, utilizing sheetsin the form of disks.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The protective screen illustrated in FIG. 1 is comprised of a frame 1with a window opening 2 of (e.g.) rectangular shape, which opening isdisposed in the field of view an individual, in particular on the visoror mask of the helmet of a motorcyclist. The screen is held in positionon the visor or mask by means of an elastic strap L fixed to the frame 1by attaching-lugs P.

Cavities in the housing 1 form a first enclosure 3 and a secondenclosure 4 disposed beyond the respective lateral sides (12, 12) of thewindow 2. A transparent film F is advanced alternately toward oneenclosure and toward the other, in the transport direction representedby arrow A. A slot 5 in frame 1 serves to guide the film in the window2.

The screen is shown in FIG. 1 in operating position, with the directionof film transport being horizontal. Alternatively, if necessary, thescreen can operate oriented vertically, with the enclosures beingdisposed horizontally and the transport direction of the film beingvertical.

As illustrated in FIG. 2, the frame has a bottom section 6 which bearshollow reels 7. In operation, the film F is alternately unrolled fromand rolled onto these reels, which extend perpendicularly to thedirection of transport of the film. The reels are housed in theaforementioned enclosures (3, 4).

The material of the film for the configuration shown is chosen to besomewhat flexible, e.g. comprising a polycarbonate, to ensure properwinding of the film on the reels.

The reels are guided in rotation by means of journals (8, 8) fixed tothe bottom section 6. Each of these journals is inserted into the hollowin one end of the respective reel 7. The other end of each reel 7 isaccommodated in a recess 9 in a cover 10.

The film F is transported by drive means comprising an electric motor Mdisposed coaxially in one of the reels 7 (a "first" such reel), whichreel is connected via the film to the second reel, which second reel hasa (re)winding spring 14 disposed on a support 15 disposed coaxially onsaid second reel. One of the ends of spring 14 is fixed to said secondreel, and the other end is fixed to the support 15.

The drive transmission for the film is provided, in known fashion, byteeth 70 fixed to the reels 7, which teeth engage two parallel rows ofopenings in the lateral edge regions of the film, similar to theperforations in a photographic film.

The film is cleaned by means of cleaning elements illustratedschematically in FIG. 3, which elements comprise brushes (or squeegeesor wipers --hereinafter, "brushes") 11 of the type used for cleaningglass. The brushes come into contact with the film F.

The brushes 11 are disposed transversely to the direction of transportof the film, against the two faces of the film, close to the lateralsides (12, 12) of the window 2. Said brushes 11 are fixedly anchored ingrooves 13, wherewith the brushes can be easily replaced when worn. Thisreplaceability allows substitution of other types of cleaningimplements, such as rotating brushes, multiridge squeegees, felts, orsponges, whereby the cleaning means can be adapted to the conditions ofuse of the screen. It is also possible to employ a cleaning liquid,contained in the enclosures (3, 4), to improve the cleaningeffectiveness in combination with the action of the brushes 11.

Where a liquid is used, in order to avoid leakage of the liquid, theenclosures (3, 4) are sealed with the aid of the brushes (squeegees orthe like) 11 which are in contact with the film (FIG. 3). In addition,O-ring joints J (FIG. 2) are disposed between the journals 8 and thereels 7, to protect the electric motor M from penetration by thecleaning liquid.

The combination of the slots 5 which guide the film F and the brushes 11which contact the film (FIG. 3) ensures that the film will be held inplace under slight tension at times when the film drive is not active.This tension prevents unwinding of the film from the reels when, e.g.,the wind blows against the window 2 while the user of the screen (alongwith the screen itself) is moving at high speed. Further, when theelectric motor M is in a stopped status it prevents rotation of thefirst reel 7, whereby one end of the film can be immobilized. The otherend of the film is subjected to the winding torque exerted by the spring14 on the second reel, which torque applies tension to the film.

The electric motor is powered by a battery (not shown) disposed in acompartment 16 in the frame 1 which compartment can be opened to theoutside, e.g. in order to replace the battery.

A switch 20, accessible from the exterior of the frame 1, is providedfor stopping the transport of the film by interrupting the electricpower supply to the battery.

The principle of operation of the protective screen will now bedescribed, particularly the means of cleaning the film F according tothe invention.

As mentioned, adverse weather conditions can result in various soilsdepositing on the film F, thereby reducing visibility. The user caninitiate cleaning of the film by actuating the switch 20, causing thebattery to supply power to the electric motor M.

As shown in FIG. 2, the electric motor which drives the film transportis controlled by a control circuit comprised of:

lever-type switches 17 configured so as to cooperate with a tab 18 onthe film F, and

a relay 19.

This control circuit is disposed interiorly of the frame 1. It enablesback-and-forth transport of the film F, without interruption. The tab18, as shown, is in contact with one of the switches 17 (designated thefirst lever switch 17).

The electric motor M then drives the first reel 7, whereby the film F iswound around said first reel. The second reel 7 is rotated via theintermediary of the film connected to the first reel, whereby the film Fon said second reel is unwound from said second reel, with concomitanttensioning of the spring 14.

During i.e. near the end of this transport, the tab 18 actuates thesecond lever switch 17 by an action in the nature of a cam. Said secondlever switch 17, causes the relay 19 to reverse the polarity of theelectric power supply to the motor, causing the motor to reverse itsdirection of rotation. The film is now caused to unwind from the firstreel, driven by both the motor M and the spring 14, wherewith saidspring tends to cause the second reel to rotate whereby the film iswound onto said second reel. Eventually, during this (leftward movementin FIG. 2), the tab 18 re-engages the first switch 17, which switchcauses the relay 19 to again reverse the polarity of the power supply tothe motor M. Thereby the cycle of the film transport begins anew.

At any time, the user can interrupt the transport of the film by merelyactuating the switch 20.

The control circuit may also be provided with means of varying the speedof film transport, in the course of a continuous or intermittenttransport, depending on the conditions of use of the screen.

FIG. 4 illustrates a variant embodiment in which the film F, as it istransported, is moved translationally in the interior of a storagecomponent 20--not same as main switch 20, which component may comprisethe arms which serve to hold the screen on the user's helmet. Theback-and-forth transport of the film in the direction of the doublearrow A is brought about by reversing the rotational direction of atleast one motor M whereby the film is driven. The film is cleaned by thecombination of the action of the brushes 11 and the transport of thefilm, as described supra.

FIG. 5 illustrates another variant, wherein two electric motors M areemployed which are disposed in the interiors of the respective reels (7,7) (designated the first reel and second reel). The control circuit issuch as to enable simultaneous control of the two motors, whereby thefilm F can be wound around the first reel and unwound from the secondreel; and wherewith the actuation of the lever-switch 17 causes areversing of the motors, whereby the film F is now unwound from thefirst reel and wound around the second reel.

Means may also be provided whereby, during the winding or unwinding, themotors can be controlled so as to rotate at different speeds, wherewiththe more slowly rotating reel provides resistance to the other reel,which other reel may be regarded as the driving wheel. In this way,tensioning of the film during the transport is assured.

In order to tension the film F when not being transported, the controlcircuit can cause the motors M to both tend to wind up the film, withthe winding torques produced being of equal magnitudes but operating inopposite directions. These oppositely directed torques are applied toopposite ends of the film, to produce the desired tension.

Control means or the like may be provided to cause the two reels torotate at different speeds in order to adjust to the variations in theeffective radii of the two reels as the film is wound thereon (orunwound therefrom). Such variations of radii tend to result invariations in the tangential speeds of the reels 7 (even when only onemotor M is employed), unless control means to adjust the angularspeed(s) of rotation are implemented.

As shown in FIG. 6, in order to be able to more effectively remove thesoils (and/or excess cleaning liquid) at the level of the brushes, onecan employ means of conferring a preferred direction of removal (arrowE); in particular, one can incline the brushes 11 with respect to thedirection of transport of the film. In this way, as the film isdisplaced, the soils present on the film tend to force ahead the soilsalready accumulated on the brushes 11. These already accumulated soils,due to the combination of the influences of the inclination of thebrushes and the direction of displacement, as well as gravity, tend tobe removed downward. The described arrangement enables one to avoidexcess accumulation of soils at the brushes 11, which would bedetrimental to the cleaning action, resulting in a less-clean film.

Another means of more effectively removing the soils (and/or excesscleaning liquid) is to arrange the brushes so as to be retractable, asillustrated in FIG. 7. One may provide cam means (not shown) fixed tothe film, having a profile such as to cooperate with the brushes 11. Asthe film is transported, the cam means cause brushes disposed on theside where the film F is being wound up to be retracted, wherewith saidbrushes disengage so as to be completely out of contact with the film;when the film transport direction is changed such that the film is nowbeing unwound on the side of the window where the brushes in questionare disposed, the brushes are brought back into contact with the film,by the action of springs 22. The cleaning of the film is accomplishedwith the aid of cleaning liquid contained in the enclosures (3, 4),wherewith the brushes 11 serve principally to wipe away excess cleaningliquid from the film F.

To avoid leakage of cleaning liquid when the brushes 11 are inretraction, sealing of the enclosures is accomplished by means ofwiping-nubs (squeegees or the like) 23 which are disposed transverselyto the direction of transport of the film and which lightly pinch thefilm F, as shown in FIG. 7.

FIG. 8 shows another (supplemental) means of avoiding major accumulationof soils at the brushes. Channels 24 are provided on the edges (12, 12)of the window 2. If one has an excess accumulation of soils which cannotbe cleaned away by the brushes 11, these channels allow said excess tobe carried away toward the exterior of the screen.

In the variant embodiment illustrated in FIG. 9, transparent sheets inthe form of discs 25 are employed. The screen is essentially in the formof a pair of eyeglasses, having a frame 1' (which may be aparallelepiped-shaped box) which bears two discs 25. The discs 25 areaxially parallel, with half of their extent disposed outside the frame1' (e.g. as shown such that said lower half is disposed in front of theuser's eyes), and the other half disposed inside the frame 1'. Anelectric motor M is disposed at a location generally between said twodiscs 25 and is oriented parallelly to the axes of the discs. The motorcontinuously rotates the discs in the opposite direction from therotational direction of the motor, via a toothed pinion (not shown)which engages peripheral teeth (not shown) on the discs 25. Brushes 11are disposed oriented radially along the discs, to effect cleaning. Theframe 1' may contain a cleaning liquid to complement the action of thebrushes.

The material of which the discs are comprised is chosen so as to be veryrigid (e.g. polyvinyl chloride, PVC), to avoid deformation. It ispossible to drive the discs 25 in alternate i.e. alternately directedangular displacements, wherewith the part of the disc which has justbeen cleaned is returned to the field of vision. With this arrangement,one may employ only a sector of a disc rather than an entire disc,thereby reducing the volume and weight of the screen device.

The invention is not limited to the exemplary embodiments describedhereinabove.

In particular:

The protective screen may be disposed over an existing protectiveelement, such as a windshield, wherewith the screen adds the feature ofsoil removal;

The protective screen may be installed so as to be removable, with theaid of suitable reversible fixing means, such as suction cups or othersuction members, whereby, e.g., the visor or mask of a helmet can beremovable;

The screen may be adapted to conform to the field of vision, e.g. thescreen may curved for application to the curved visor or mask of ahelmet;

The screen in the form of a disc or portion of a disc (as in theembodiment according to FIG. 9) may have variant shapes and forms, e.g.may have an elliptical or other shape rather than a circular disc-shape;

The lever-type switch 17 for the control circuit may readily be replacedby a photocell, phototransistor, or other mechanical or optical orelectronic means capable of detecting the passage of the tab 18;

The brushes 11 may be disposed somewhat distant from the enclosures (3,4) rather than being disposed near the lateral sides 12 of the window 2;

The film F may have a plurality of zones with dimensions generally equalto those of the window 2, wherewith said zones may be subjected tovarious mechanical or chemical treatments to improve the qualities ofthe film (e.g. anti-scratching, antifogging, polarizing, tinting) and ingeneral render it adaptable to a variety of ambient and weatherconditions;

The control circuit may comprise a programmable integrated circuit whichcan control the transport of the film so as to locate the various zones(mentioned above) in the window 2 as the user desires;

The teeth 70 which engage perforations in the film F may readily bereplaced by axial openings in the reels, wherewith the ends of the filmmay penetrate into said openings; or the borders of the film may bearadhesive strips which adhesively bond them to the reels;

Mechanical means of driving the transport of the film may be providedinstead of electrical; e.g., one may provide a ratchet mechanismoperated by pulling laterally on a string or the like;

The protective screen may be configured generally as illustrated in FIG.9 but with only a single disc;

The protective screen, in the form of a film or disc, may be employed inapplications wherein reduced visibility is a safety risk, e.g. on visors(or masks) of helmets, goggles or the like, cameras, photographicapparatus, masks (such as industrial safety masks), headlights, beacons,automobile windshields, and rear-view mirrors; or the screen may beinstalled in a transparent housing which protects a machine tool of thetype which uses a spraying system to distribute the cutting oil.

The invention relates to an optical protective screen for improvedvisibility, comprised of drive means to transport (move or displace) atransparent sheet or film in a transport direction, which sheet or filmis disposed in a field of vision of an optical apparatus or humanobserver.

Cleaning means comprising brushes (or squeegees or the like), orientedgenerally transversely to the transport direction of the sheet or film,are disposed on at least one side of the field of vision and are appliedagainst said sheet or film.

What is claimed is:
 1. An optical protective screen for improvedvisibility, comprised of:a drive mechanism for transporting atransparent sheet in a transport direction, which sheet is disposed in afield of vision of an optical apparatus or a human observer; cleaningbrushes oriented generally transversely to the transport direction ofthe sheet; said brushes being disposed on at least one side of the fieldof vision and applied against said sheet, and a frame having a windowopening with lateral sides, which frame has two enclosures disposed nearthe lateral sides of the window, wherein the sheet includes a film whichis transported in the window between the two enclosures, thetransporting being alternately in one direction and then the other withaid of said drive mechanism, and the brushes being disposed at or nearthe respective sides of the window.
 2. A screen according to claim 1,further comprising two respective hollow reels disposed in theenclosures wherewith the film is wound up onto and unwound from saidreels.
 3. A screen according to claim 2, wherein the drive mechanismincludes an electric motor disposed coaxially in one of said reels,designated the first reel, which first reel is connected via the film tothe other reel which has a rewinding spring that is disposed on asupport disposed coaxially on said other reel.
 4. A screen according toclaim 2, wherein the drive mechanism includes two electric motors, eachof which is disposed coaxially in a respective one of said reels.
 5. Ascreen according to claim 1, wherein the frame includes storagecomponents disposed at said enclosures.
 6. A screen according to claim1, wherein the enclosures contain a cleaning liquid and are providedwith a seal to prevent leakage of said liquid, said seal including thebrushes which are disposed at the respective sides of the film.
 7. Ascreen according to claim 6, wherein the brushes are retractable whenthe film is displaced in one direction, and are extendable to acontacting status when the film is displaced in an opposite direction soas to wipe away excess cleaning liquid; and wherein the seal includeswiping-nubs that are disposed transversely to the transport direction ofthe film that can lightly pinch said film.
 8. A screen according toclaim 1, wherein the brushes are inclined with respect to the transportdirection of the film.
 9. A screen according to claim 1, wherein theenclosures include means for removal of soils, which means are disposedat the lateral sides of the window.
 10. An optical protective screen forimproved visibility, comprised of:a drive mechanism for transporting atransparent sheet in a transport direction, which sheet is disposed in afield of vision of an optical apparatus or a human observer; cleaningbrushes oriented generally transversely to the transport direction ofthe sheet, said brushes being disposed on at least one side of the fieldof vision and applied against said sheet, wherein the sheet is presentin the form of a disc driven in rotation; and the brushes are disposedalong a radius of said disc.
 11. An optical protective screen forimproved visibility, comprising:a drive mechanism for transporting atransparent sheet in a transport direction, which sheet is disposed in afield of vision of an optical apparatus or a human observer; cleaningbrushes inclined with respect to the transport direction of the sheet,said brushes being disposed on at least one side of the field of visionand applied against said sheet.